The present invention has particular application to a terminal post in a cable barrier. However, the present invention can also be used in other situations, where a cable is being held under tension, and it is desirable to release the cable, should the post become deformed by an impact.
For ease of reference only the present invention will now be described in relation to cable road barriers.
Terminal posts which release a cable upon an vehicle impact are well known.
The applicant has previously devised an improved anchor-body and terminal post for a cable barrier which is fully described WO2007/129915. This improved terminal post overcomes the ramp and snag situations that can occur when a vehicle impacts the anchor cables of a cable barrier.
The applicant has also invented another terminal post the subject of NZ Patent Application No. 579282 which represents a further improvement to the invention in WO2007/129915 in that it provides a terminal post of unitary construction which is quick, easy and relatively cheap to manufacture yet still achieves the advantages of the terminal post taught in WO2007/129915. Conversely, the terminal post detailed in WO2007/129915 whilst effective in achieving its aims requires a separate anchor body to be fabricated and attached to the upright member of the terminal post which is relatively time consuming and expensive.
The terminal post of the present invention therefore aims to provide a quick release mechanism which is equally effective, as both of the terminal posts discussed above are, are: reducing or preventing an inclined cable anchoring system from acting as a ramp or snag, during impacts from a number of different angles.
It would therefore be useful to have a cable-barrier system or release mechanism that could withstand impact from collisions from both forward and reverse directions. So in addition to reverse direction impacts it can also release at least one downwardly extending anchor-cable of a terminal post of a cable-barrier, in situations where the anchor-cable(s) are capable of acting as a ramp or snag during a collision.
The terminal posts of WO2007/129915 and NZ Patent Application No. 579282 both require the fabrication of separate assemblies or a post of a unique construction. It would therefore be useful if there could be provided a terminal post which was of similar construction to standard barrier posts and only required minimal modifications to achieve the aforementioned advantages. As this would prevent having to stockpile terminal posts.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
Throughout this specification, the word “comprise”, or variations thereof such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.